A wind driven electrical power generating apparatus, such as a windmill, is commonly utilized to convert the energy present in wind into electrical energy. In particular, windmills typically include a number of blades or wings coupled to an output shaft. The wings are rotated or otherwise moved by the force of the wind acting thereon. The output shaft is typically coupled to an input shaft of an electric generator or other type of energy converter such that when the input shaft is rotated by the wind acting upon the wings, the generator produces electrical energy.
However, such electrical power generators typically require the input shaft thereof to be rotated at a relatively high speed in order to produce desirable quantities of electrical energy. For example, the input shaft of the generator may have to be rotated at 100 revolutions-per-minute in order to generate a single kilowatt (kW). Hence, windmills which have heretofore been designed typically require the output shaft to be rotated at a relatively high speed in order to correspondingly rotate the input shaft of the generator at a relatively high speed.
Such a speed requirement typically precludes efficient use of windmills in areas in which relatively low wind velocities are present. In particular, high wind velocities are generally required to drive the wings and hence the input shaft of the generator at the high speeds which are required to efficiently drive the generator.
What is needed therefore is a wind driven electrical power generating apparatus which overcomes one or more of the above-mentioned drawbacks. What is further needed is a wind driven electrical power generating apparatus which generates electrical power in the presence of relatively low wind velocities.